This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A076460 Sum of squares of numbers that can be written as t*n + u*(n+1) for nonnegative integers t,u in exactly one way. 5
 1, 103, 1130, 6070, 22355, 64981, 160468, 351660, 703365, 1308835, 2297086, 3841058, 6166615, 9562385, 14390440, 21097816, 30228873, 42438495, 58506130, 79350670, 106046171, 139838413, 182162300, 234660100, 299200525, 377898651, 473136678, 587585530, 724227295 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES Fred. Schuh, Vragen betreffende een onbepaalde vergelijking, Nieuw Tijdschrift voor Wiskunde, 52 (1964-1965) 193-198. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 FORMULA a(n) = n*(n+1)*(7*n^4+2*n^3-6*n^2-n+1)/6. G.f.: x*(1+96*x+430*x^2+288*x^3+25*x^4)/(1-x)^7. MAPLE seq(1/6*n*(n+1)*(7*n^4+2*n^3-6*n^2-n+1), n=1..30); MATHEMATICA CoefficientList[Series[(1 + 96 x + 430 x^2 + 288 x^3 + 25 x^4)/(1 - x)^7, {x, 0, 50}], x] (* Vincenzo Librandi, Dec 30 2013 *) PROG (MAGMA) [n*(n+1)*(7*n^4+2*n^3-6*n^2-n+1)/6: n in [1..50]]; // Vincenzo Librandi, Dec 30 2013 CROSSREFS Cf. A076389, A076461-A076465. Sequence in context: A023355 A113629 A034180 * A245495 A097726 A262273 Adjacent sequences:  A076457 A076458 A076459 * A076461 A076462 A076463 KEYWORD easy,nonn AUTHOR Floor van Lamoen, Oct 13 2002 EXTENSIONS More terms from Vincenzo Librandi, Dec 30 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 12 12:30 EST 2019. Contains 329958 sequences. (Running on oeis4.)